影响酶解去除薏苡仁淀粉过程的关键参数考察

Investigation of Key Parameters in Process of Removal of Starch in Coicis Semen by Enzymatic Hydrolysis

目的:考察影响高温α-淀粉酶酶解去除薏苡仁中淀粉的关键参数,为薏苡仁总多糖的应用提供参考。方法:以还原糖含量及碘液检试样品颜色变化作为定量及定性指标,在单因素试验基础上,通过正交试验考察酶解温度、酶用量、酶解时间、酶解p H对薏苡仁中淀粉酶解程度的影响。结果:最佳酶解参数为酶用量600 U·g-1,酶解温度75℃,酶解p H 6.0,酶解时间120 min;薏苡仁总多糖水提液中还原糖质量分数约25%,且碘试液检测不变色,薏苡仁总多糖纯度达76.63%,较未去除淀粉的薏苡仁总多糖纯度54.41%显著提高。结论:高温α-淀粉酶可简单、快速的去除薏苡仁中淀粉,有利于高纯度薏苡仁总多糖的获得。

Objective： To provide a reference for application of total polysaccharides in Coicis Semen by investigating effect of key parameters on high temperature α-amylase enzymolysis for starch in Coicis Semen. Method： Take the content of reducing sugar as a quantitative indicator and color change after iodine solution testing as a qualitative indicator, based on single factor tests, orthogonal test was adopted to investigate effects of the amount of enzyme, hydrolysis temperature, hydrolysis pH and reaction time on amylohydrolysis. Result： Optimal parameters were as follows： the amount of enzyme 600 U·g^-1, enzymolysis temperature 75℃, enzymatic pH of 6.0, enzymolysis time of 120 min. The content of reducing sugar in extract of total polysaccharides in Coicis Semen was about 25% , meanwhile, color of samples did not alter after iodine solution testing. Purity of total polysaceharides in Coicis Semen was 76.63% , which showed a great improvement by comparing with 54.41% of samples without removing starch. Conclusion： High-temperature a-amylase can remove starch from Coicis Semen readily and rapidly, it is conducive to extraction of total polysaccharides.